are always just.[97]

"It is the right of a State," said that profound moralist and statesman,
Sir James Mackintosh, "to take all measures necessary for her safety if
it be attacked or threatened from without: provided always that
reparation cannot otherwise be obtained; that there is a reasonable
prospect of obtaining it by arms; and that the evils of the contest are
not probably greater than the mischiefs of acquiescence in the wrong;
including, on both sides of the deliberation, the ordinary consequences
of the example as well as the immediate effects of the act. If
reparation can otherwise be obtained, a nation has no necessary, and
therefore no just cause of war; if there be no probability of obtaining
it by arms, a government cannot, with justice to their own nation,
embark it in war; and, if the evils of resistance should appear on the
whole greater than those of submission, wise rulers will consider an
abstinence from a pernicious exercise of right as a sacred duty to their
own subjects, and a debt which every people owes to the great
commonwealth of mankind, of which they and their enemies are alike
members. A war is just against the wrongdoer when reparation for wrong
cannot otherwise be obtained; but is then only conformable to all the
principles of morality when it is not likely to expose the nation by
whom it is levied to greater evils than it professes to avert, and when
it does not inflict on the nation which has done the wrong, sufferings
altogether disproportioned to the extent of the injury. When the rulers
of a nation are required to determine a question of peace or war, the
bare justice of their case against the wrongdoer never can be the sole,
and is not always the chief matter on which they are morally bound to
exercise a conscientious deliberation. Prudence in conducting the
affairs of their subjects is in them a part of justice."

These are the true principles by which Mexico should have judged the
controversy between us, before she rejected all our efforts to
negotiate, and forced our government to prepare for hostilities.

* * * * *

The idea of war, for mere conquest, seems now to be obsolete among
civilized nations. To political dominion, as exhibited in the various
governments of the old world, and in most of the new, geographical
limits are definitely assigned. This fact must, hereafter, greatly
modify the objects of war, by narrowing them to _principles_